A number of methods of producing trihalosilanes have been disclosed. For example, the reaction of hydrogen chloride with zero-valent silicon has been described. In addition, trichlorosilane has been produced by passing silicon tetrachloride, hydrogen, and hydrogen chloride over zero-valent silicon at 600° C. Further, trichlorosilane has been produced by passing hydrogen and silicon tetrachloride over silicon particles in a first stage, adding hydrogen chloride to the effluent from the first stage, and then passing the effluent and hydrogen chloride over more silicon particles optionally containing a catalyst (i.e., CuCl) in a second stage. Finally, trichlorosilane has been produced by passing hydrogen, silicon tetrachloride, and hydrogen chloride over zero-valent silicon containing homogeneously distributed copper silicide.
While the art describes methods of producing trichlorosilane, the methods have some limitations. For example, many of these processes employ zero-valent silicon. Since zero-valent silicon is typically produced by the highly energy-intensive carbothermic reduction of silicon dioxide, using it directly adds costs to these processes.
Therefore, there is a need for more economical methods of producing trihalosilanes that avoid the direct use of zero-valent silicon.